This invention relates to an ultrasound probe and an ultrasound diagnostic apparatus, particularly in which the ultrasound probe and the ultrasound diagnostic apparatus thereof change the formation of the transmitted ultrasound beam.
In an ultrasound diagnostic apparatus which transmits an ultrasound beam to a target object for ultrasound imaging, an ultrasound probe for transmitting and receiving an ultrasound beam is connected to the ultrasound diagnostic apparatus. A one-dimensional probe with transducer elements placed in the row direction has an effective resolution performance in the azimuth direction; however, the performance in the elevation direction is determined by the fixed aperture focused in a fixed range. On the other hand, for the purpose of enhancing the performance in the elevation direction, many types of multi-row probes, including a two-dimensional probe, are under development.
When the ultrasound diagnostic apparatus generates a two-dimensional ultrasound image such as a B-mode image, it is preferred to use the one-dimensional probe which transmits an oval-shaped ultrasound beam having high resolution performance in the azimuth direction. Also, when the ultrasound diagnostic apparatus generates a three-dimensional ultrasound image using the two-dimensional probe, it is preferred to use the two-dimensional probe or the multi-row probe, which transmits an ultrasound beam of a true circle, and having equal performance in the azimuth direction and the elevation direction. An example of the two-dimensional probe is disclosed in Japanese unexamined patent 2003-290228. The two-dimensional probe disclosed in Japanese unexamined patent 2003-290228 controls transducer arrays placed two-dimensionally using a matrix switch.
Unfortunately, even if the multi-row probe, such as the two-dimensional probe, is used for generating an ultrasound image, the resolution performance in the azimuth direction remained low. It is desirable that the performance in the azimuth direction of the multi-row probe is enhanced.